The present invention is related to an advanced network processor (ANP) which serves as a concentrator in data communication systems, in particular, to a processor which receives data from many subscriber lines, packages and formats the data and retransmits the data via trunk lines which lead to packet switching networks for communication and transmission to other subscribers or terminals.
In the past, when telephonic and telex communications was most important, interconnection between various subscribers was simple. It involved the direct routing of subscriber lines to local central switching exchanges from where the calls or telex data was transferred across great distances to other central switching stations and redirected to a desired subscriber. Interconnection was simple because all calls or data orignated from devices with similar characteristics. It was either a telephone or perhaps a telex machine. Carriers and interconnect companies employ large machines which receive information from many subscriber lines and combine them for transmission over great distances by using techniques such as time division multiplexing (TDM) or other suitable means for transmission.
With the recent explosive penatration of the computer and data terminal into the home and the office, a need for transmission and exchange of data between these devices has arisen. Accordingly, data is being transferred from one subscriber to another through the facilities of carriers and interconnect companies. Data subscribers can call and receive large quantities of data which originate from special data base facilities many of which provide their own transmission and interconnection networks.
Since the data subscribers employ various machines of different data transmission characteristics, carriers, interconnect companies and data base providers are required to provide facilities which can accomodate the various data terminals. Consequently, carriers and interconnect companies provide dedicated hardware which is capable of interfacing and understanding the protocol of each specific machine for which a line is provided. If the device which is at the end of a subscriber line is changed, it is necessary to physically alter and exchange hardware which is associated with a specific subscriber line in order to accomodate a differently typed subscriber. Furthermore, the present day facilities are such that great investments of money and time are required in order to increase the capacity of a given facility. Present day network processors or concentrators, as they are known, are very large machines which accomodate a large number of subscribers and which are quite expensive. Since these machines must be dedicated and taylored for particular subscribers, planning for future growth is hampered due to uncertainty as to the type and nature of data communication equipment which will eventually be connected to the network. In sum, these machines are not modular and consequently cannot grow with a growing market of subscribers. They are inflexible and can not be easily retrofitted to handle various data types or a mixture thereof in accordance with marketing requirements.